THE BASIC MECHANISMS OF DISTORTION AND DIMENSIONAL ERRORS WHICH OCCUR DURING THE MANUFACTURE OF COMPOSITE PREPREG PARTS AND TOOLING ARE DISCUSSED AND CLASSIFIED. PRACTICAL METHODS OF QUANTIFYING AND ELIMINATING SUCH ERRORS ARE CONSIDERED IN RELATION TO BOTH STRUCTURAL PART AND TOOLING MANUFACTURE, WHICH REPRESENT AN ALTERNATIVE TO THE EMPIRICAL METHODS USED THROUGHOUT THE COMPOSITES INDUSTRY.